A micro-blood-sample collection tube is a commonly used tool for collecting blood in medical departments such as hospitals. Such a micro-blood-sample collection tube is made of a glass tube with small inner diameter, which opens at both ends and is of pass-through construction. One end of the micro-blood-sample collection tube is contacted with the blood to be collected when collecting blood. The blood to be collected is made to enter automatically the interior of the micro-blood-sample collection tube by means of a capillary action. There is generally a requirement for volume when collecting blood, therefore volume scales are marked on the micro-blood-sample collection tube, such as 5 microliters, 10 microliters, 15 microliters, 20 microliters, . . . , 50 microliters. Because the speed at which the blood to be collected enters the micro-blood-sample collection tube is greater, frequently a medical staff does not have enough time to remove the micro-blood-sample collection tube at the moment the blood reaches the required scale, such that actual amount of the collected blood is more than the required amount of the collected blood. Thus, when the blood is removed from the micro-blood-sample collection tube, not only is it necessary to insert the micro-blood-sample collection tube into a latex red dripper and then press the latex red dripper with fingers so as to remove the blood from the micro-blood-sample collection tube, but also necessary to control the removed amount, therefore the whole process takes longer time, and it is inaccurate and inconvenient. An auto-suction micro-blood-sample collection tube made of plastic material is manufactured by a medical instruments manufacturer in US, wherein a micro-blood-sample collection tube and a compressive air bag are made as a whole piece during manufacturing, and ventilation hole(s) is provided at a prescribed scale on tube wall of the micro-blood-sample collection tube. The ventilation hole is clogged with the blood when the blood reaches the prescribed scale, such that the capillary action is stopped, and the blood no longer enters the micro-blood-sample collection tube, so as to complete quantitative micro-volume blood sampling. Then, it is possible to remove the blood by pressing the air bag with fingers. The whole blood-sampling process is accurate, quick and convenient. However, because the auto-suction micro-blood-sample collection tube is made of plastic material, the inner wall of the micro-blood-sample collection tube has hydrophobicity, it is hard for the capillary action to occur to suck blood, thus it is necessary to perform hydrophilic treatment on the inner wall of the plastic micro-blood-sample collection tube during manufacturing. This process takes longer time, with very low production efficiency, which significantly increases product cost and hinders popularization and application of the auto-suction micro-blood-sample collection tubes. So far, low-cost auto-suction micro-blood-sample collection tubes without hydrophilic treatment have not needed to emerge.